What consumers eat 17 selected for their relevance to the objectives of the survey. Therefore, the results efficacy for calculating the energy and nutrient intake is limited. Methods such as 24-hour recalls and food records, on the other hand, do not necessarily reflect habitual intake. In highly demanding surveys, such as those requiring weighed diaries of multiple days, a significant proportion of subjects may drop out, intro- ducing bias in the sample. The representativeness of the survey population, the potential of the data(e.g. suitability for energy and nutrient calculations), the elements that may affect the reliability of the collected data and the accuracy of the results(e. g. participation rate), are all factors affecting the suitability of a dietary survey to be used for international comparisons(Haraldsdottir, 1991). The error possibly introduced by the application of various food composition databases for estimating nutrient intakes should also be considered The documented lack of compatibility of food composition data from various countries(Deharveng et al, 1999)may compro mise the validity of the observed relationships. It is generally acknowledged that dietary intake cannot be estimated without rror and each method has its strengths and weaknesses. The knowledge of the methods limitations and of the nature and the magnitude of the errors will lead to a more scientific and sensible interpretation of the results. Although dietary surveys differ widely in the accuracy of their estimates of quantities of food eaten, these differences are usually not listed when the results are presented. These dif- ferences are seldom obvious and must be borne in mind when various surveys are compared The often prohibitive cost of special dietary surveys may limit the European coverage of data collection. Being expensive and labour intensive, such surve are regularly undertaken only in a limited number of countries, usually those with robust economies and years of experience in the field. In the modern world of rapid changes, however, nutrition surveillance and intervention programmes should make use of dietary surveys that have built-in mechanisms of continuity over time and extensive coverage 2.5 Dietary data in Europe: European surveys In Europe, there is a need for sources of dietary data that would provide a regular and comparable flow of information. A limited number of studies on document- ing and monitoring the dietary intake in Europe have been conducted. The EPIC and SENECA projects are examples of studies that developed procedures to allow the collection of harmonised data across countries. DAFNE is an example of a European project that aimed at achieving post-harmonisation of data already collected 2.5.1 The DAta Food NEtworking AFNE) initiative The DAFNE initiative aims at exploiting the HBS-derived data for nutritional purposes and developing a cost-effective food databank, based on data collectedselected for their relevance to the objectives of the survey. Therefore, the results’ efficacy for calculating the energy and nutrient intake is limited. Methods such as 24-hour recalls and food records, on the other hand, do not necessarily reflect habitual intake. In highly demanding surveys, such as those requiring weighed diaries of multiple days, a significant proportion of subjects may drop out, intro￾ducing bias in the sample. The representativeness of the survey population, the potential of the data (e.g. suitability for energy and nutrient calculations), the elements that may affect the reliability of the collected data and the accuracy of the results (e.g. participation rate), are all factors affecting the suitability of a dietary survey to be used for international comparisons (Haraldsdóttir, 1991). The error possibly introduced by the application of various food composition databases for estimating nutrient intakes should also be considered. The documented lack of compatibility of food composition data from various countries (Deharveng et al, 1999) may compro￾mise the validity of the observed relationships. It is generally acknowledged that dietary intake cannot be estimated without error and each method has its strengths and weaknesses. The knowledge of the method’s limitations and of the nature and the magnitude of the errors will lead to a more scientific and sensible interpretation of the results. Although dietary surveys differ widely in the accuracy of their estimates of quantities of food eaten, these differences are usually not listed when the results are presented. These dif￾ferences are seldom obvious and must be borne in mind when various surveys are compared. The often prohibitive cost of special dietary surveys may limit the European coverage of data collection. Being expensive and labour intensive, such surveys are regularly undertaken only in a limited number of countries, usually those with robust economies and years of experience in the field. In the modern world of rapid changes, however, nutrition surveillance and intervention programmes should make use of dietary surveys that have built-in mechanisms of continuity over time and extensive coverage. 2.5 Dietary data in Europe: European surveys In Europe, there is a need for sources of dietary data that would provide a regular and comparable flow of information. A limited number of studies on document￾ing and monitoring the dietary intake in Europe have been conducted. The EPIC and SENECA projects are examples of studies that developed procedures to allow the collection of harmonised data across countries. DAFNE is an example of a European project that aimed at achieving post-harmonisation of data already collected. 2.5.1 The DAta Food NEtworking (DAFNE) initiative The DAFNE initiative aims at exploiting the HBS-derived data for nutritional purposes and developing a cost-effective food databank, based on data collected What consumers eat 17